This dataset was taken from the list of OpenIntro dataset files found at https://www.openintro.org/data/.

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mammals

This data set includes data for 39 species of mammals distributed over 13orders. The data were used for analyzing the relationship betweenconstitutional and ecological factors and sleeping in mammals. Twoqualitatively different sleep variables (dreaming and non dreaming) wererecorded. Constitutional variables such as life span, body weight, brainweight and gestation time were evaluated. Ecological variables such asseverity of predation, safety of sleeping place and overall danger wereinferred from field observations in the literature.

Variables

• species - Species of mammals
• body_wt - Total body weight of the mammal (in kg)
• brain_wt - Brain weight of the mammal (in kg)
• non_dreaming - Number of hours of non dreaming sleep
• dreaming - Number of hours of dreaming sleep
• total_sleep - Total number of hours of sleep
• life_span - Life span (in years)
• gestation - Gestation time (in days)
• predation - An index of how likely the mammal is to be preyed upon. 1 = least likely to be preyed upon. 5 = most likely to be preyed upon.
• exposure - An index of the how exposed the mammal is during sleep. 1 = least exposed (e.g., sleeps in a well-protected den). 5 = most exposed.
• danger - An index of how much danger the mammalfaces from other animals. This index is based upon Predation and Exposure. 1= least danger from other animals. 5 = most danger from other animals.

Source

http://www.statsci.org/data/general/sleep.txt

Taken from: https://www.openintro.org/data/index.php?data=mammals.